Unity: All versions | Appodeal SDK: 2.15.4 or higher

The error "AAPT: error: resource android:attr/lStar not found" happens if your project doesn't support the functionality of API 31, which is required for androidX libraries used by ad networks.

The error example from Unity Editor Log:

FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':launcher:processReleaseResources'.
> Android resource linking failed
AAPT: error: resource android:attr/lStar not found.
error: failed linking references.

To solve the error:

Setup Target API level to 32 in File → Build Settings → Player Settings → Other Settings.